FOR years Prime Minister Benazir Bhutto's major political foe, the Pakistani Army, now plays an uneasy and reticent role in propping up her fragile rule. As troops moved in to quell ethnic tumult in Sind Province, an officer complained bitterly.
``This is putting great strains on the Army,'' he says of the military's massive new presence to restore law and order in Karachi, the Sindi capital. ``The government should have been able to take some political steps.''
Last week, with her tormented home province near collapse, Ms. Bhutto was forced to call out the Army to contain a new explosion of ethnic strife. Despite border tensions with rival India, more than 20,000 troops took over the streets of Karachi and Hyderabad where they will stay for three months or longer, military and government sources say.
The Army's deepening involvement in Sind is a troubling and embarrassing setback for Bhutto, whose beleaguered government has lurched from crisis to crisis in surviving 18 months in political power.
Bhutto spent years in jail resisting martial law and crusading to restore democracy and human rights before winning national elections and taking office in December 1988.
Hopes that she, as a Sindi, could quiet the ethnic vendettas among Sindi nationalists and immigrants from India, known as mohajirs, and other groups helped assuage Army jitters over her leadership.
However, the latest violent outburst, in which more than 200 died and Sind police massacred women and children demonstrators, angered the military and its chief, Gen. Mirza Aslam Beg.
Pressures mounted for Bhutto to dismiss her Sind government and bring the province under central rule. And as troops arriving in Hyderabad were welcomed with calls to bring back martial law, worries revived that a disenchanted military could turn on the prime minister and try a return to power.
``The situation in Sind is very dangerous; time is running out,'' says a veteran political observer in Karachi. ``She has exhausted her usefulness to the Army. Sind is her Achilles' heel.''
Until the outbreak in Sind, Bhutto, who rules under the watchful eye of the military and the powerful president Ghulam Ishaq Khan, had been gaining firmer political ground, analysts say.
She has buried her differences with the influential president and appeased the Army by steering clear of military spending and other matters. In turn, her tenure has boosted Pakistan's image overseas and rehabilitated the Army's reputation at home.
Bhutto has aggressively defended the Muslim insurgency in Indian Kashmir, a stance that has skillfully silenced her toughest domestic foes, but brought Pakistan dangerously close to war with her larger neighbor.
In recent days, however, India has pulled back troops from front-line border positions and offered conciliatory measures to defuse tensions with Bhutto's government.
To her credit, her backers and some critics say, Bhutto has freed the press and eased rampant human rights abuses. And weak as she is, there is no viable alternative, diplomats say.
``No matter what has happened, she still has a better chance than anyone else,'' says a diplomat.
Still, Western and Pakistani observers say that corruption is pervasive in her government, although Bhutto denies the charge and challenges her accusers to prove it.
Critics say that business schemes involving concessionary land grants for luxury hotels, satellite projects, and stock exchanges have been linked to her ministers, political cronies, and her husband, Asif Ali Zardari.
She has a very good human rights record and the press is free, says Kamal Azfar, a former member of Bhutto's party who was ousted and now supports the opposition. ``However, this level of corruption I didn't expect. This is the most astonishing, the most corrupt and the most unsophisticated government I have ever seen.''
Nonetheless, the disintegration in Sind remains her most dangerous challenge, analysts say.
Just 18 months ago, Bhutto's Pakistan People's Party, which is strongest among rural native Sindis, came to power in the province in a coalition with the urban-based mohajir party, the Mohajir Qaumi Movement (MQM).
Then mounting crime and ethnic clashes pushed Sind into a dangerous slide and unraveled the Bhutto-mohajir political alliance. Last fall the MQM bolted to join anti-Bhutto politicians; and four months ago, student gangs, backed and armed heavily by the rival political parties, launched a vicious urban war in Karachi and Hyderabad, Sind's two largest cities.
Last month's outburst was particularly stunning. In the aftermath of the Hyderabad police massacre, gangs attacked buses and trains, killed journalists, and battled each other with rocket launchers and other sophisticated weapons.
Bhutto canceled a trip to gain Muslim countries' support after a visit to embattled Hyderabad.
``People asked her why she was traveling around the world and saying India should stop killing Kashmiris when people in Sind were being killed,'' says an aide.
At presidential and Army urging, Bhutto's provincial government has called an all-party peace conference. Yet she maintains a hard line, branding the MQM ``terrorists'' in recent interviews, accusing mohajirs of launching ``a guerrilla uprising,'' and charging India, which contends Pakistan is helping Kashmiri separatists, with fomenting trouble in Sind.
All sides say it will be difficult to restart the political process.
``As long as the Army is around, there is peace,'' says a provincial government official and Bhutto loyalist. ``But there can be no lasting peace until we get a working relationship with the MQM, and that will take a long time.''
Meantime, the Army warily watches Bhutto's grip loosening in Sind.
Analysts familiar with the Army say General Beg, who has firmly backed Pakistan's democracy experiment, faces growing military disillusionment - a restiveness that deepens with each wave of violence in Sind.